Carburetor



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BY E E g lTORMEY R J 5 m 1 Gm, NMR, IIR SU. SBC Em M0104 e .H n F L Oct. 11, 1938.

Patented oet. -11, 193s UNITED STATES PATENT OFFICE cAnBUnE'ron Lester H. Messinger, Jr., Trumbull, Conn., assignor to Messinler Devices, Incorporated, Bridgeport, Conn., a corporation of Connecticut Application Deeember 12, 1935, seria No. 54,1133

Claims.

This invention relates to newy and useful improvements in carburetors.

The invention provides means whereby the fuel discharged by a vacuum operated accelerating 5 pump of a carburetor is forcedk by the pump into u. receptacle and is drawn from said receptacle into an engine fed by the carburetor onlywhile the carburetor throttle valve is open and there is a suction in the engine.

The objects and advantages ofthe invention ,will become apparent from a consideration of the following detailed description taken in connection with the accompanying drawing wherein there is shown a satisfactory embodiment of the invention. However, it is to be understood that the invention is not limited to the details'disclosed but includes all such variations and modifications as fall within the spirit of the invention and the scope .of the appended claims.

In the drawing:-

Fig. 1 is a vertical sectional view through a carburetor embodying vthe features of the invention;

Fig. 2 is a top plan view of one corner portion of the carburetor andvshowing the invention;

Fig. 3 is a view'partly in elevation and partly in section showing a receptacle employed;

Fig. 4 is a detail sectional view showing the carburetor fuel pump in discharged position;

Fig. 5 is a detail sectional-view of the economizer valve; and a Fig. 6 is a' detail sectional view of a check valve.

Referring in detail to the drawing a carburetor of the down-draft type is shown and the same comprises upper and lower sections I0 and II secured together by screws I2. Within the carburetor is any or the usual venturi I3 between the strangler valve I4 and the throttle valve I5. In the float chamber I 6 the fuel is maintained at the level indicated by the line II by means of a float (not shown) having an arm I8 located to operate a valve I9 controlling the admission of gasoline from any sourcerthroughvthe connection 20. Y

'I'he carburetor includes a vacuum operated fuel pump generally designated 2i and comprising a chamber 22 forming they pump cylinder.v Within said cylinder there is arranged pistons 23 and 24 connected by a rod 25 about which is a coil spring 26 bearing at its respective ends against the piston 23 and a collar 21. In Fig. 1 spring 26 is compressed and the pistons 23 and 24 are in the positions occupied by them when .the pump is loaded while in Fig. 4 the `spring is expanded and the 55 pump discharged. The spring constantly tends (Cl. E61-34) to maintain the pistons in the positions of Fig. 4 and to return them to such positions when moved therefrom.

By means of a cross passage 28 the upper end of the pump cylinder 22 is placed in communic'a- 5 tion with the upper'end of a vertical passage 29 which lthrough a lateral branch III communicates with the fuel passage 3i below the throttle valve I5. 'Ihrough the described passages'suction from the engine, while the latter is operating. l0 will serve to exhaust air from above the piston 24 and the piston assembly, including pistons 2l and 24 and the rod 25, will be drawn upwardly compressing the spring 26 bringing about loading of the pump.

A lateral passage 32 from the lower end of the pump cylinder communicates through a one way valve Il with the float chamber I6. Valve (see Fig. 6) is a ap valve including a valve proper 50 opening downwardly and normally is 20 open to permit of the flow of fuel from the oat chamber into the chamber 22. On downward movement of the piston 23 under the urging of the spring 26 pressure is applied to the fuel in the chamber 22 and the passage 32 and valve 5l 25 moves upwardly against its seat 5I preventing the fuel in the pump from being forced back into the float chamber. .p

Below the pump cylinder is a well 34 communi-'- eating through a passage 25 with a fuel jet or 30 nozzle 26 which in the present case is the power jet of the carburetor. vAn economizer valve l1 is arrangedl to close off communication between the jet 26 and the pump when the pump is in loadedv position. 'Ihis valve Il includes a stem 52 35 carrying a valve proper 53 and the lower end portion of such stem is guided by a spider 54. Between the spider and the valve 53 a spring 55 is disposedv about the stem 52 and under normal conditionsis effective for maintaining valve 5I 40 against its seat. The arrangement of the valve 21 is such that if there is no other escape for fuel as the pump discharges then the valve is forced open and the fuel Vis discharged through the nozzle or jet 36.

Arranged at one side of the body of the car. buretor is a. small tank or receptacle 26 adaptedA to receive the fuel discharged by the pump as will later be fully set forth. While this tank or receptacle is shown outside the body of the car- 5o buretor it will become apparent as the description proceeds that it might equally well comprise a chamber formed within the body of the carburetor. Therefore, while in subsequent portions of the -description and in the claims the tank or re- 55 ceptacle 38 is referred to as a- "receptacle" it is to .be understood that such word is used as including a separate tank as shown or a compart-V ment or chamber formed in the main body of the carburetor or at any other convenient location.

The passage 32 communicates with a Well 33 at the lower side of the valve 33 and also communicating with the we ll is one end of a tube 40 forming a passage between said well and the interior of the receptacle 38 at the upper end thereof. Since tube 40 connects with well 33 it places the receptacle in communication with the oat chamber I6 through the valve 33 and with the pump throughthe lateral passage 32. When the piston 23 is drawn to its upper position by suction on the piston 24 the pump is loaded with fuel drawn from the oat chamber through the valve 33.

Thereafter on the suction or vacuum being reduced the spring 26 acts and the piston 23 descends to discharge the pump. At this time the valve 31 is closed and the pressure on the fuel lforces valve 33 closed-and the fuel is discharged by the pump through the tube `4|) into the receptacle 33. Since the fuel has an escape through the tube 40 sufficient pressure to force open the valve 31 is not generated and such valve remains closed until its stemis engaged by the piston l23.as in Fig. 4 when the valve is forced and held open'.

Heretofore in carburetorsi of the type shown the pump 2| discharged only through the nozzle 36. The arrangement was such that the pump was operated to loaded position While there was suction in the engine equipped with the carburetor and then on reduction ofthe suction or vacuum as by opening the throttle valve the spring 26 of the pump would act Vto discharge it and the fuel would be forced through the nozzle 361.

With such an arrangement the pump would discharge through nozzle 36 when the engine ignition was cut oif and the engine stopped and the discharged fuel would simply run into they V overcome these difficulties and prevent waste of fuel I provide the receptacle 38 and the connections thereton so that each time the pump disi charges the fuelpasses to the receptacle and is taken therefrom at such times as the fuel is required by the engine.

A tube 4| has vone end connected with the interior of the receptacle adjacent the lower end thereof and as shown suchtube is attached to a wall of the fuel passage 3| by a fitting 42 and extending through said wall has its other end portion inclining upwardly forming a nozzle '43. Nozzles 36 and 43 together with the usual cap jet 44 extend under the usual deilector 45 supported by across piece 46 spanning the venturi |3.

Fuel discharged into the receptacle 38 remains thereinwhile the throttle is closed or while the 1 air inlet valve of my patent above referred to is 4| and into the engine. As the engine operates under conditions imposing a high degree of vacuum in the venturi portion of the carburetor fuel is drawn through the tube 4| until the supply in the receptacle is exhausted.

Receptacle 38 is of such capacity in its portion below the fuel level indicated by the line |'I as to be capable oi' containing that volume of fuel representing several discharges of the pump 2|. In its upper portion above the fuel level the receptacle is provided with holes or perforatlons 4`| forl the admission of air. Owing to the presence of these holes when the fuel is exhausted from the lreceptacle air is drawn through the tube 4| and nozzle 43 and a siphonic action cannot be set up through the tube 4|, receptacle 38 and tube `4|! to the iioat chamber of the carburetor. While the receptacle may be supported by the tubes 40 and 4| it is preferred to attach it to the main body ofthe carburetor as by a strap 48 secured to the receptacle by a screwv 49 and to the carburetor by one of the screws I2.

It will be apparent that on thefuel in the receptacle reaching the level indicated by the line I1 should any additional fuel be forced into the receptacle the excess will ilow out of the upper end of the nozzle 43. Therefore the receptacle cannot be filled up to the inlet opening or to the vent openings so that the latter may always function to admit air and prevent the setting up of a siphonic action from the nozzle 43 back through the 'receptacle to the oat chamber of the carburetor.

The invention is not limited to carburetors of the type or construction shown and obviously changes may be made without departing from the spirit of the invention or the scope of the appended claims.

Having thus set forth the nature of my invention what I claim isz- 1. In a carburetor including a venturi, a fuel chamber, a nozzle for supplying fuel from said chamber to said venturi, a pump communicating with said chamber and including vacuum operated means to move it to loaded position and spring means to .operate it to discharge fuel on reduction of vacuum on said means, a receptacle, a passage connecting the receptacle, pump and nozzle, a valve in said passage in position to cut off the nozzle whereby as the pump discharges it forces fuel into .the receptacle, said valve arranged to be held off its seat by the pump when the latter is in discharged position, and-a passage connecting said receptacle with the venturi for the passage `of fuel from the receptacle to an engine fed by the carburetor.

2. In a carburetor including a venturi, a fuel chamber, a nozzle for supplying fuel from said chamber to said venturi, a pump comunicating Awith said fuel chamber and including vacuum operated means to move it to loaded position and spring means to operate it to discharge fuel on reduction of vacuum on said means, a receptacle, a passage connecting the receptacle, pump and nozzle, a valve in said passage in position to cut off the nozzle whereby as the pump discharges it forces fuel into said receptacle, means whereby the valve is held -oif its seat while the pump is in discharged position, and a passage connecting said receptacle with the venturi for the passage of fuel from the receptacle to an engine fed by the carburetor.

3. In a carburetor including a venturi, a fuel chamber, a nozzle in the venturi, a pump communicating with said fuel chamber and including Cil vacuum operated means to move it to loaded position and spring means tcl operate it to-discharge fuel on reduction of vacuum on said means. a receptacle, a passage connecting the discharge of the pump with the upper end portion of the receptacle whereby on each discharge of the pump fuel is delivered to the'receptacle, and-a passage connecting the lower end portion of the receptacle with said nozzle for the passage of fuel from the receptacle to an engine fed by the carburetor.

4. In a carburetor including a venturi and a nozzle in the venturi, a fuel chamber, a vacuum operated fuel pump, a receptacle, a passage connecting said chamber, receptacle, pump and nozzle, a valve to cut oif communication between the passage and chamber when there is a pressure on the fuel in the passage, a valve in the passage to cut oil the nozzle whereby as the pump discharges it forces fuel through the passage into the receptacle and as the pump moves to loaded position it draws fuel from the chamber through the first valve, means whereby the second valve is held ofi its seat while the pump is in discharged position, and a passage from the receptacle to the venturi whereby fuel is drawn from the receptacle under conditions of high Yvacuum in the venturi. y

5. In a carburetor including a venturi, a fuel chamber, a nozzle in the venturi, a pump communicating with said fuel chamber and including vacuum operated means to move it to loaded position and spring means to operate it to dis charge fuel on reduction of vacuum on said means, a receptacle, means connecting the receptacle with said nozzle for the passage of fuel from the receptacle to an engine fed by the car'- buretor, said connecting means and receptacle arranged and constructed whereby fuel i's drawn' into the engine from the receptacle'only when there is a suction on said nozzle, and means whereby on reduction of vacuum on said pump due to operation of means other than the throttle and at different times from normal breaking of the vacuum by opening of the throttle all fuel discharged by the pump is delievered to and retained by said receptacle whereby to prevent waste of fuel when the vacuum pump discharges while there is no suction on said nozzle and whereby to have such fuel available to the engine through said nozzle on suction' being again applied to the nozzle.

6. In a carburetor including a throttle, a fuel pump adapted to be operated to charged position by vacuum, spring means to operate the pump to discharged position, aV receptacle, an outlet from the receptacle and through which fuel is drawn into an engine fed by the carburetor, said outlet and receptacle arranged and constructed whereby fuel is drawn into the engine from the receptacle only while there is a suction in the engine, and means whereby on reduction of vacuum on said pump due to operation of means other than the throttle and at times different from normal breaking of the vacuum by opening of the throttle all fuel discharged by the pump is delivered to and retained by said receptacle whereby to prevent waste of fuel when the vacuum pump discharges and there is no suction in said engine and whereby to have such fuel available to the engine through said outlet on reestablishment of suction in the engine.

7. In a carburetor, a fuel pump adapted to be operated to charged position by vacuum' and other means to operate the pump to cause it to discharge fuel, a receptacle of a capacity to contain several complete discharges of said pump. means connecting the receptacle with the carburetor for the passage of fuel therethrough from the receptacle to an engine fed by the carburetor, said connecting means and receptacle arranged and constructed whereby fuel is drawn into the engine from the receptacle only when the engine is exerting a suction pressure on the carburetor,

and means whereby on reduction of vacuum onsaid pump due to operation of means other than the throttle and at different times from normal breaking of the vacuum by opening of the throttle all fuel discharged by the pump is delivered to and retained by said receptacle whereby to prevent waste of fuel when the vacuum pump discharges and there is'no suction on said carburetor and whereby to have such fuel available the engine through said connecting means on reestablishment of suction in the carburetor.

8. In a carburetor including a venturi and a throttle valve below the venturi, a fuel chamber, a pump communicating with the fuel chamber and including vacuum operated means to move it to loaded positionand other means to operate it to discharge fuel on reduction of vacuum on said means, a receptacle, a passage connecting the receptacle with the 'Venturi portion of the carburetor for the passage of fuel from the receptacle through said venturi to an engine fed by the carburetor said passage and receptacle arranged and constructed whereby fuel is drawn into `the engine from the receptacle only on opening of said throttle valve while there is a suction in the engine, and means whereby on reduction of vacuum on said pump dueto operation of means other than the throttle and at different times from normal breaking of the vacuum by opening ofthe throttle all fuel discharged by th pump is delivered to and retained by said receptacle whereby to prevent waste of fuel when the vacuum pump discharges and there is no suction in the engine and whereby to have such fuel available to the engine through said passage on reestablishment of suction in the engine.

9. In a carburetor including a throttle, a fuel 1 pump adapted to be operated to charged position suction in the engine, means whereby on reduction of vacuum on said pump due to operation of means other than the throttle and at different times from normal breaking of the vacuum by opening of the throttle all fuel discharged by the pump is delivered to and retained by said receptacle whereby to prevent waste of fuel when the vacuum pump discharges and there is no suction in the engine and whereby to have such fuel available to the engine through said outlet on reestablishment of suction in the engine, and said receptacle vented in its upper portion to prevent the setting up of a siphonic action through the receptacle on exhausting of the fuel therefrom. 10.` In a carburetor having a venturi and a nozzle in the venturi, a fuel supply chamber, a vacuum operated fuel pump communicating with said chamber, a receptacle vented above the fuel level in said chamber, said receptacle below said level having a capacity to hold several discharges from said pump, a passage connecting the recep-A on reduction of vacuum on Said pump due to operation o means other than the throttleand lat clierent times from normalbreaklng of the vacuum by opening ofthe throttle all fuel discharged by said pump is delivered to and retained by said receptacle whereby to prevent waste of fuel when said pump discharges in the absence of high vacuum in the venturi and whereby to have such 5 fuel available to the engine through sai-:l venturi lon suction being reestablished therein.

LESTER H. MESSINGER, JR. 

